"Mixing organics and water is a very appealing astrobiological recipe," Lorenz said by email.

Stiles added: "It gives us one more place to look for life."

Important Find

This is a "very important finding," said Christophe Sotin, a geophysicist at NASA's Jet Propulsion Laboratory who was not involved in the study.

But it needs to be confirmed, he said, by watching what happens to Titan's rotation as the winds shift in upcoming years.

If the crust's drift doesn't slow down and reverse course as the wind pattern changes, something else is causing the deviation from the previously expected rotation.

But if the ocean does exist, it would raise to four the number of large moons of Saturn and Jupiter thought to have such subterranean seas.

"Large reservoirs of water, a condition for life to form and develop, [would thus be] a common feature in the solar system," a team led by Sotin wrote in a commentary article in tomorrow's issue of Science.

But even without that carrot, the prospect of an ocean simply adds to Titan's mystique.

"Titan is very Earthlike compared to other bodies," Stiles said. "We see lakes—not water, but liquid. We see dunes, like in the Sahara desert. We see mountains and channels that look like river channels. It's one of the few other bodies that has weather."